supports

I have finally started making the stunts on my freeride trail. Most of the stuff is made of wood for drops,skinnies,and wall rides. My only concern is are the supports strong enough. Can you help me in the right way to make the supports or even post pictures of the supports you built on your trail.

The taller the bridge the deeper we try and go. As stated above 3ft is generally all that is needed. I always try to pound some rocks in around the posts before refilling them with dirt. Seems to help stiffen things up.

The most we're gone is 4ft deep on this "Tower of Power" start gate for our Local Super-D trail.

(don't mind the semi ghetto railing. We built the full tower in the pouring rain the night before a race so by the time we got to the railing looks were 2nd to function. New railing getting built later this month along with a back ramp to we can ride up.)